Design And Performance Study Of A Segmented Intelligent Isolation Bearing

Seismic control of engineering structures is a new field of seismic resistance of engineering structures.Unlike traditional isolation methods,it resists external excitation by changing dynamic parameters such as stiffness,damping and natural frequency of isolation structures.Aiming at the defect of single isolation effect of traditional isolation bearings,this paper develops a segmented intelligent isolation bearing based on practical engineering problems,which can meet the requirements of seismic fortification under three seismic intensities that are frequent intensity,basic intensity and rare intensity respectively.The dynamic mechanical properties of the developed isolation bearings are tested,and the dynamic mechanical model suitable for the isolation bearings is established.The main contents of this paper include:1.The theoretical study of segmented intelligent isolation bearing.The isolation principle of segmented intelligent isolation bearing is theoretically analyzed.For the isolation bearing developed in this paper,the lateral stiffness of rubber layer and magneto-rheological elastomer is analyzed,the plate-shell model is simplified and its elastic stiffness is given.Finally,a theoretical formula for the output of the segmented intelligent isolation bearing is established,which provides a basis for the subsequent determination of the size of the isolation bearing.The theoretical basis of magnetic circuit structure is introduced.2.Preparation and testing of magnetorheological elastomers and shear-thickened magnetorheological plastics.Magnetorheological elastomer and shear-thickened magnetorheological plasticity used in isolation bearings were prepared by ourselves,and their dynamic mechanical properties were tested.The changes of shear storage modulus and damping factor of the two materials with magnetic field under different strain and frequency conditions were analyzed.3.Design and development of segmented intelligent isolation bearing.A new type of segmented intelligent isolation bearing is designed for different seismic intensity.The feasibility of the bearing is studied in terms of technical index and structure.The mechanical properties of the arc plate layer of the bearing are analyzed by finite element analysis software ABAQUS.The equivalent magnetic circuit of the isolation bearing is established,and the magnetoresistance is calculated.The magnetic circuit structure of the isolation bearing is simulated by ANSYS software.Finally,the design parameters of the isolation bearing are given,and the full-scale segmented intelligent isolation bearing is manufactured.4.Performance test and dynamic model of segmented intelligent isolation bearing.The mechanical properties of the isolation bearing under small displacement,medium displacement and large displacement are tested respectively,and the hysteretic characteristics of the force-displacement are analyzed.The concepts of equivalent stiffness and equivalent damping are introduced to analyze the changes of the stiffness and damping of the isolation bearing,and the theoretical data and experiments are compared.Combining rheological model and phenomenological model,the dynamic mechanical model of the isolation bearing is established,and the parameters of the mechanical model under different working conditions are identified by MATLAB software.